1. Field of the Invention
The present invention relates to a bridgeless power factor correction device capable of reducing switching loss.
2. Description of the Related Art
Recently, national governments around the world have urged the effective use of energy in conformity with energy efficiency policies, and in particular, effective use of energy in electronic products or home appliances is widely recommended.
Thus, according to such recommendations, a remedial circuit for effectively using energy has been applied to power supply devices supplying power to electronic products, home appliances, and the like.
The remedial circuit may be, for example, a power factor correction circuit. A power factor correction circuit is a circuit for switching input power to adjust a phase difference (power factor) between a current and a voltage of the input power to effectively transfer power to a rear stage.
In general, a power factor correction circuit may be classified as a passive type power factor correction circuit and an active type power factor correction circuit.
A passive type power factor correction circuit employs a method for correcting a power factor with an inductor or a capacitor, and in particular, it is known to have a limitation in power factor correction in a single phase.
An active type power factor correction circuit employs a method of correcting a power factor by performing switching by a combination of an inductor and a switching element by using a boost type topology. However, the active type power factor correction circuit has relatively low efficiency, a high internal current, voltage ripples, electromagnetic interference (EMI) noise, and the like, and thus, its application to a middle or large-scale power source device is not easy.
In particular, in the case of the power factor correction circuit, switching loss is generated in the process of switching input power.
Patent document 1 below relates to a bridgeless boost converter having a power factor correction (PFC) circuit, which, however, does not disclose a configuration for improving switching efficiency in power conversion.